The only reason I am really concerned about the Kovalchuk injury is because he is such a warrior. To see him wince in pain like that and skate of the ice favouring his shoulder so much could only something bad.

I cant think of a shoulder injury that isnt atleast 1 month or longer of time off

Can't be some kind of bruise or something? I'm not a shoulder injury expert (because I haven't had one... yet), but I assume that's still a possibility in some capacity. Temporary limitation of movement, soreness, etc. Probably out a week or two. Something along those lines mildly possible?